The present invention relates generally to the testing of electrical and electronic circuits and devices, and more specifically to the testing of arc fault circuit interrupters.
U.S. patent application Ser. No. 10/937,487 filed Sep. 9, 2004 entitled APPARATUS AND METHOD FOR DETECTING ARC FAULTS (the '487 application) discloses an arc fault circuit interrupter (AFCI) device that can reliably detect and distinguish between electrical arc faults and nuisance loads, and trip a circuit breaker to disconnect power to a load in the event electrical arcing has occurred. Electrical arc faults are generally non-periodic arcing events that may be caused by corroded, worn, aged, or otherwise damaged wiring or wire insulation, and/or faulty electrical connections. For example, electrical arcing can occur between the ends of a two wire conductor, between a conductor and ground, or between respective conductors connected to a load. In contrast, nuisance loads are generally associated with periodic electrical events that may be caused by triac-controlled dimmer circuits, switch-mode power supplies, appliance thermostat switching, drill current transitions, random line voltage spikes, or EMI bursts. Whereas electrical arcing often has the capability of igniting adjacent flammable material and therefore generally constitutes a fire hazard, nuisance loads are typically incapable of creating such a hazardous condition. Because the arc fault circuit interrupter disclosed in the '487 application can distinguish between electrical arc faults and nuisance loads with a high degree of reliability, the AFCI device can successfully disconnect power to a load upon detection of electrical arcing while being significantly less susceptible to nuisance tripping.
To assure that the AFCI device disclosed in the '487 application is operating properly during manufacture and test and in the field, a tester may be employed to apply simulated electrical arcing to the device, and to determine whether the device performs an expected tripping operation in response to the simulated arc fault. However, testing such an AFCI device can be problematic because not only must the device be tested to verify tripping in response to electrical arcing, but it must also be tested to verify that no tripping occurs when the device is connected to a nuisance load.
Heretofore, the requirement of AFCI device testers to simulate both electrical arcing and nuisance loads has not been fully met. It would be desirable to have a tester for an arc fault circuit interrupter that addresses this requirement.